Replace CL_REQUIRE/CL_PROVIDE(cl_random_def) with portable code.

The order of initialization of non-local objects in different compilation units
is not specified in C++. Hence special care should be taken to avoid static
initialization order fiasco. CLN solved the problem with some evil (GCC
specific, and even GCC-version-specific) hack. Replace it with a technique
similar to one used in STL to initialize std::cout and friends.

include/cln/random.h

@@ -33,7 +33,15 @@ inline uint64 random64 (random_state& randomstate)
 
 // Ein globaler Zufallszahlengenerator.
 extern random_state default_random_state;
-CL_REQUIRE(cl_random_def)
+class cl_random_def_init_helper
+{
+	static int count;
+public:
+	cl_random_def_init_helper();
+	~cl_random_def_init_helper();
+};
+static cl_random_def_init_helper cl_random_def_init_helper_instance;
+
 // Das ist der Default-Generator.
 inline uint32 random32 (void)
 	{ return random32(default_random_state); }

src/base/random/cl_random_def.cc

@@ -3,8 +3,6 @@
 // General includes.
 #include "cl_sysdep.h"
 
-CL_PROVIDE(cl_random_def)
-
 // Specification.
 #include "cln/random.h"
 
@@ -15,6 +13,20 @@ namespace cln {
 	
 random_state default_random_state;
 
+int cl_random_def_init_helper::count = 0;
+cl_random_def_init_helper::cl_random_def_init_helper()
+{
+	if (count++ == 0) {
+		default_random_state = random_state();
+	}
+}
+
+cl_random_def_init_helper::~cl_random_def_init_helper()
+{
+	if (--count == 0) {
+		// Nothing to clean up?
+	}
+}
+
 }  // namespace cln
 
-CL_PROVIDE_END(cl_random_def)